Recent technological advances in coupling electron microscopy to analytic techniques involving electron-electron interactions have been applied to neurochemistry and neuropathology. Localization of heavy metals was successfully studied at the subsellular level in experimental lead poisoning, cis-platinum treatment, and manganese exposure. Clinically, brain tissue from patients with Alzheimers disease and amyelotrophic lateral sclerosis was studied for increased local concentrations of aluminum, lead, and other toxic metals.